It has long been known in the CO.sub.2 laser art that an electrically excited CO.sub.2 gain medium will partially decompose into CO and oxygen, and that products of this decontamination tend to suppress lasing action. Oxygen in quantities as small as 1% leads to arcing between the laser electrodes and subsequent loss in optical power. One prior art approach to this problem has been to use a heated platinum wire to encourage the recombination of CO and oxygen to form CO.sub.2. This method has the obvious drawbacks of requiring an additional power supply to heat the platinum wire and also of increasing the heat within the laser discharge volume.
Several experiments have been made to test the use of an ambient temperature catalyst, the materials including activated copper, activated platinum and hopcalite, a commercial mixture of magnesium oxide, copper oxide and trace quantities of other oxides. This material is available commercially from the Mine Safety Appliances Company. An article by C. Willis and J. G. Purdon in the Journal of Applied Physics, Vol. 50, No. 4 in April 1979 discloses the use of hopcalite in an external gas loop joined to the active laser volume, but in which the catalyst is not present within the laser volume. An article by R. I. Rudko and J. W. Barnie in the Proceedings of the SPIE, Vol. 227, entitled CO.sub.2 Laser Devices and Applications, published in 1980, reports the successful application of a solid ambient temperature catalyst within a laser cavity, but does not give any detail as to the type of catalyst and arrangement of the catalyst in the cavity. Such details were said in that article to be proprietary.